The present invention pertains to devices and methods for maintaining water level in a reservoir. Sensing water level in reservoirs of varying styles and application has been an important need in many industries. The need to ensure that a fluid remains at a set level within these reservoirs makes it necessary to economically sense when the level has dropped below the prescribed setting and provide a means to activate a filling mechanism to return the fluid to its proper level or activate an alarm or other control functions.
There are many methods in the prior art for sensing level, yet many are expensive and difficult to apply. Probes of varying shapes and size have predominantly been used as a means to sense water level because of their simplicity of manufacture and relative ease of use. However, the circuitry needed to integrate the probes to provide control capabilities can become intricate and expensive.
As direct current (DC) causes corrosive breakdown of the probe material due to electrolysis, alternating current is typically used to minimize the effects of electrolysis.
With this in mind, prior art devices have incorporated the aforementioned probes in conjunction with expensive current sensing devices that use magnetic field sensing, optics, logic matrices, or capacitance networks to induce a secondary indicator signal to activate the control circuitry. What is needed is a simple and inexpensive device to sense water levels and enable control of water flow devices using direct current electrical power.